1. The Field of the Invention
The present invention generally relates to a structure of surface-adhered the light emitting diode display device, and more particularly, to a light emitting diode display device having a lower circuit board and an upper circuit board stacked on the lower circuit board forming a protruded circuit board, wherein the protruded circuit board is covered by a frame which securely joints with the upper and lower circuit board for effectively preventing the sidewall of the frame of the display device flit outwardly, as well as to reinforce the structure to resist an external force.
2. Description of the Related Art
With the rapid advances in high-tech electronic information industry, several valuable electronic products have advanced functions to provide users prompt service and convenience, leading to a high-tech civilization. When enjoying the pleasure brought such high-tech products, at work or in daily activities, the high-tech products have become a part of users' life. Among these valuable high-tech products, only few of them comprise light-emitting diode display for displaying the execution of speed, time, channel and other operational information.
The general light-emitting diode display has a light-emitting diode crystal and IC on the circuit board, and the arrangement of circuit board may be a single layer or a double layer. The single layer circuit board has copper foil loop or IC, and light-emitting diode crystal positioned on its upper and lower side, with an outer frame covering directly onto the circuit board, or alternatively, a resin is injected to joint the outer frame with the circuit board. For the double layer circuit board, after stacking the two boards, the copper foil loop or IC, and light-emitting diode crystal are set on the circuit board. Next, a frame is directly covered onto the resulting structure or alternatively, a resin is injected to joint the outer frame with the circuit board. Referring to FIGS. 7 and 8, the elevational view of the conventional light-emitting diode display device and the sectional view taken along the line a—a of the structure shown in FIG. 7 respectively are shown. The conventional light-emitting diode display A comprises a circuit board B, an IC B1, a light-emitting diode crystal, and a frame C. The IC B1 and the light-emitting diode crystal are disposed on the circuit board B, and the frame C is directly covered onto the circuit board B and a resin D is injected securely adhere the frame C to the circuit board B. However, such conventional light-emitting diode display A has the following defects.
The frame C is jointed with the circuit board B (single or double layer) only with one side. Because the joint surface thereof is small, and therefore the jointing cannot be substantially secure.
Because of the small joint surface, the transfiguration or loss of original shape could easily occur due to change of the surrounding temperature, and may result in flitting up of the frame on the sidewall or the frame may come loose.
Because of the weak structure of the sidewall of the frame, the frame could easily flit up or become loose causing loose contact between the IC B1 and the light-emitting diode crystal and thereby adversely affecting the display function of the light-emitting diode display A.
Accordingly, it is highly desirable to improve the structure of the conventional light emitting diode display to overcome the above defects.